How to Train for a Marathon - Better Nutrition

How to Train for a Marathon

Want to train for a marathon? Here's how to get started.
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Have you ever thought of running a marathon? Races can be strong motivation to stick with a fitness program, accomplish a seemingly impossible goal, raise money and awareness for a worthy cause, or simply make fitness-minded friends. No matter what your current fitness level, here are five things you should know.


Plan Ahead

“It’s not a test you can cram for,” says Janet Hamilton, an exercise physiologist and professional running coach ( for more than 25 years. “I really encourage people, if they want to train for a marathon, get some miles under your feet first,” she says. “Learn how to run and understand the strategy of metering out your effort for the given distance.” This holds true for a marathon (26.2 miles), a half marathon (13.1 miles), a 10K (6.2-mile), and a 5K (3.1-mile) race.

Understand Your Body

Training your body for distance running means building what Hamilton calls “infrastructure,” internal components that enable you to perform. “You’re asking your body to make changes on a cellular level, to build more blood vessels, to build more enzymes, to build more mitochondria,” she says. “These are little cellular changes that have to take place if you’re going to be able to improve as a runner.”

Find Your Starting Point

Whether you’re an avid runner, a couch potato, or somewhere in between, there’s a way to start that’s right for you. If you aren’t already running, Hamilton recommends starting by walking. Work up to walking at least 10 miles a week, and do this consistently for at least a month, before starting to run. And then, as long as you don’t have any injury problems, begin interspersing some short, 30-second bouts of running, and gradually increase the running portions (see Online Resources for more details).

On the other hand, if you’ve been running regularly for at least six months and clock at least 25 miles per week, including one weekly long run of at least 6 miles, you could start a training program for a marathon—as long as you aren’t dealing with any injuries. And you could be ready in another six months. But even then, it might be wiser to make your first race a shorter one. “I like people to have some experience before biting off a marathon,” says Hamilton.


“Stretch every day,” says Hamilton, “only to the point of a gentle pulling sensation, not to the point of discomfort.” Hold each stretch for about 30 seconds.

Ramp Up Gradually

Walk or run four or five times a week, aiming for distance rather than speed, and increase your total weekly mileage by no more than 5 to 10 percent per week. On a five-day schedule, one walk or run should be longer than the others—about 30 percent of the total. Two others should each be about 20 percent of the total, and the remaining two should be shorter and less strenuous. This approach challenges your body on the longer days and allows it to recover and build strength on the shorter and rest days.

Avoid Injuries

Most often, injuries stem from increasing distance too quickly, running too fast, or not paying attention to strength and flexibility. All-around strength training is a must for everyone, and for walking and running, hip strength is especially important, as it helps to prevent knee problems. Squats are the best exercise.

Stretching calf muscles, hamstrings, and quadriceps, in the front of the thighs, will help prevent injuries. “Stretch every day,” says Hamilton, “only to the point of a gentle pulling sensation, not to the point of discomfort.” Hold each stretch for about 30 seconds.

And, no matter what length of race you aim for, she says, “Give yourself plenty of time to train.”

Know When You’re Ready

When your body is ready for a race, says Hamilton, this is what you should be doing stably and without injuries, for three or four weeks:

Total miles per week

Long run distance (once per week)

5K (first time)



10K (first time)

18 or more


Half marathon

30 to 35

11 to 13


40 or more

18 to 20

For 5K races, higher weekly mileage and long runs will improve performance for experienced runners.

To avoid being exhausted when the race starts, taper off, meaning gradually cut back on distances, for about three weeks before a marathon, about two weeks before a half marathon, about a week before a 10K, and about three days before a 5K.

Start Walking to Fitness 

Not quite ready for a marathon? Although walking isn’t the only thing we need to stay in good shape, it’s a great way to get active before gradually adding more intensity. If you don’t already walk at least 30 minutes a day, here’s one way to get started, from the American Council on Exercise:

On 5 days per week, walk each day for:

Week 1: 20 minutes

Week 2: 22 minutes

Week 3: 24 minutes

Week 4: 26 minutes

Each week, keep increasing the daily time by 2 minutes until you reach 40 minutes per day. The following week, walk for 50 minutes a day. And then the following week, after each 5 minutes of walking, jog or run for one minute. Depending upon your own fitness level, you can shorten the daily time by doing higher-intensity spurts more often. And, add some weight training to your regimen.

Online Resources

How to start a walking program:

Sample walk-to-run transition program:

More running tips and coaching resources:



Training During Pregnancy

While traditional wisdom tells women to “take it easy” during pregnancy, new evidence shows it’s not harmful, and may even benefit your baby, to stay active.



Staying in shape benefits bone, balance, and overall quality of life—and it’s never too late to start.